Continuous casting apparatus



Dec. 30, 1941. B. ZUNCKEL CONTINUOUS CASTING APPARATUS Filed Nov. 19, 1938 2 sheets-rsheet 1 'Dec. 30, 1941. B. ZUNCKEL 2,258,100

7 I CONTINUOUS CASTING APPARATUS v Filed NOV. 19, 1938 2 Sheets-Sheet 2 Patented Dec. 30, 1941 UNITED STATES PATENT OFF-ICE I .com'muoos 2.2 msaarus v Berthoid Zunckel, Osnabruck, Germany Apparatus for the manufacture of extruded cast elements is already known which consists of a fixed mould through which is conducted the melt which solidifies to an extruded cast element, On account of the friction occurring between the chill mould wall and the extruded cast element a normal building up of the texture in the outerzone' which solidifies first is prevented by displacement of the crystals which form. Hereby the constitution of the surface of y 1 Claims. (01. 22-513) cordingly a sliding of the solidifying melt onthe walls of the moulds does not occur, and better solidifying conditions are obtained since bybearing of the cast rod on the wall of the chill the element is unfavourably affected and the tight bearing on the cooled wall of the chill mould which is necessary for an effective cooling is in part lost. Also the solidity of the outer skin which forms first is impaired.

It has already been attempted to overcome the unfavourable influence of the slipping of the extruded cast element in the mould, by using mould parts which are fastened to endless chains as casting moulds which travel with the element'to be cast. Casting devices of this kind have, however, the disadvantage that disproportionately large masses have to be moved, since a great number of moulds is necessary in this process. The paths of the individual mould parts must in fact be made so long, that the latter have time to give up again the amount of heat which they have .taken up during contact with the cast elements before they come into contact again with the liquid metal. Further these devices have the drawback that it is not possible to convey the moulds which release the extruded cast elements back to the beginning of the chill moulds more rapidly than they travel with the casting block.

There is therefore necessaryat least such a number of, mould members as corresponds to double the actual length of the chill mould. Moreover the moved mould parts cannot be kept at the necessary even temperature by internal cooling and in addition their peculiar type of construction and the arrangements for their motion prevent direct cooling of the cast element so that it is notpossible to make cast bars free from enclosures of slag and pipes with fine rained structure. The subiectof the invention is a process for the manufacture of cast elements which permits the avoidance of the disadvantages attaching to the previously known processes of continuous casting. It is characterised essentially by the feature that the molten material is cast between two or more divisible permanent moulds which can be moved independently of each other with the cast element whereby the mould halves lowermost at the time are lifted from the'cast bar, and placed upon the ,mould uppermost at the time for the purpose of lengthening the hollow space of the mould. In these operations the mould parts describe curves which correspond to overlapping right angles; Ac-

mould, and thus an increased cooling effect is obtained.

In order to avoid enclosures of slag it is necessary that the solidifying process be so influenced that as little liquid melt as possible is the casting mould.

In the process according tothe invention this is brought about by the part of the cast bar released from the mould, which part only has a solidified crust on its outer surface, being cooled directly from the outside so that the leading off of the heat from the liquid part is effected substantially by way of the solidified part of the cast bar. In this way it is possible to limit the amount of liquid metal present in the chill mould to a minimum and in such a way to give it no time for any slag enclosure worth mentioning.

In the process according to the invention, only a quite small number of moulds is necessary and it is even possible to manage with two moulds.

Two examples of constructions of devices for carrying out the process are shown diagrammatically in the drawings. v 1

Fig. 1 is a side elevation of an apparatus for the manufacture of cast elements with two movably mounted moulds.

Fig. 2 is a plan view of the device of Fig. 1. Fig. 3 is a vertical section through a casting device with mechanically moved divisible moulds. Fig. 4 is a plan view. partly in section, of a device according to Fig. 3.

The divisible moulds I and 2 (Figs. 1 and 2) are mounted so as to be vertically displaceable on guiding elements e. g. the uprights 3 and 4, the two halves of each mould being carried by arms 5, 6 rockable in horizontal planes so as to open and close the moulds. For this purpose a sleeve is slidably arranged on each upright and suspended from a counterweight 9. Each sleeve 30 has a lower and an upper flange 3| and 32 respectively, and the arms 5 and i of a mould encompass the pertaining sleeve 30 in superimposed position and bear upon the horizontal upper face 33 of the flange 3|.

The process of working is such that when a predeternuned liquid level is reached in the upper mould I, thelower mould 2 which is moved with the bar I is opened by its arms 5 and 6 being swung apart. Then, its sleeve 30 together with the divided mould is raised to a level above the originally upper mold I. Thereafter, the arms 5 and 8 are swung back in a horizontal plane so as to close the mould 2 and to place it upon the now lower mould I. This process is continuously present in repeated, so that a continually growing cast element is producedwithout a relative movement between the latter and the moulds occurring, as long as both are in contact. The cast element is carried by a lowering device 8, which is lowered to-the same degree as liquid metal flows in. The same motion is executed by moulds I and I owing to their friction with the cast element. The moulds are provided with cooling devices of which the inlet and outlet pipe connections are denoted by In and H. In addition there is provided a separate cooling device I! which cools directly from the outside the part of the casting released from the mould. Direct cooling can also be obtained by lowering the casting into water.

Instead of allowing the moulds to be moved by the casting, it is sometimes advantageous to bring about the motion mechanically. In the 'formof construction according to Figs. 3 and 4,

the permanent moulds I, I mounted in the guide tracks l3, I4 are positively moved forward in the direction of travel of the cast element by motordriven gear wheels l5 which engage in corresponding racks li on the moulds. hen a predetermined position is reached the ower divided having a horizontal surfaceadapted to support a section part during upwardly and horizontally said guide so as to be displaceable up and downmg in takes place through a casting device 2!,

or the mould parts can also be so constructed that on one side or on both sides there remains a narrow gap 22 through which the liquid metal introduced into a pourer 23 passes into the interior of the mould.

If circumstances require, the guides I3, Il may be so formed that they narrow or widen slightly towards the bottom, so that, corresponding to the shrinkage or later expansion of the solidifying bar the mould parts are pressed on the latter for better heat transfer. For, cooling the individual parts of themouid, ducts 24 are provided through which the cooling agent, e. g.

ward in a vertical direction, in operative engagement with said guide, and vertically movable means to support said parts when moved in horizontal planes at both ends of their vertical movemen 3. In an apparatus forthe production of extruded cast elements, including a plurality of bipartite permanent mold sections adapted to be superimposed with respect to each other, that improvement which consists'in the provision of carriers for the parts of said mold sections respectively, and guides for said carriers, said carriers being mounted on said guides so as to be shiftable in a vertical direction and individually swlngable in a horizontal plane.

4. A device as claimed in claim 3 wherein an individual guide is provided for each co-ordinate pair of mold section parts.

5. In an apparatus for the production of extruded cast elements, including a-plurality of. bipartite permanent mold sections adapted to be superimposed with respect to each other, that improvement which consists in the provision of means for advancing the mold sections mechanically and in a vertical direction with the growing cast element, two lifting means on onposite sides of the path of advancementof said mold sections, and horizontal tracks to carry the two parts of the section which is the lowermost at a time on their way towards said lifting means.

6. In an apparatus for the production of extruded cast elements, including a plurality of bipartite permanent mold sections adapted to be superimposed with respect to each other, that water, flows. Apart from this cooling through the moulds direct cooling of the part of the cast element extending out of the mould can be provided, e. g. by means of a device similar to the device I2 in Fig. l. u

By means of moulds of different cross section it will be apparent that elements of different cross section, of any desired length can be cast.

By the insertion of cores it is also possible to cast hollow blocks.

I claim:

1. In, an apparatus for the production of eximprovement which consists in the provision of means for guiding said mold sections downward when in engagement with each other, rack bars attached to said mold sections, motor driven gear wheels adapted to engage said rack bars so as to advance the mold sections downward with the growing cast element, two lifting means, and

horizontal tracks for individually carrying the two parts of the section which is the lowermost at a time to said lifting means respectively, whereby the lowermost section may be displaced so as to constitute the topmost section of a mold.

7. In an apparatus for the production of extruded cast elements, including a plurality of bipartite permanent mold sections adapted to be superimposed with respect to each other, that improvement which consists in the provision of means for guiding said mold sections downwards while their parts are in engagement with each other, means for cooling theindividual parts of each section, means forguidingin a horizontal plane the two parts of that section which is the lowermost at a time, while the parts are disengaged from each other, and means for guiding the last mentioned two parts from said horizontal plane upward to the top level of the mold.

m'mom ZUNCKEL. 

